12" up is not a great distance, could be chewed upon by a canine standing on hind legs. How far into the ground?
Might be better and easier to lay across top of ground, or buried a couple inches.
Here's some examples of anti-dig aprons.
Good examples of anti-dig apron installation.
https://www.backyardchickens.com/threads/wire-around-coop.1110498/#post-17093528
https://www.backyardchickens.com/threads/new-coop-project.1169916/page-2#post-18481208
What are the dimensions and gauge of the mesh you are using?
Hardware cloth....1/2" x 1/2" x 19 gauge?
Chicken Wire.....1" from flat to flat x 23 gauge?